1 /* 2 * Copyright (c) 1982, 1986, 1989, 1991 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)kern_exit.c 7.45 (Berkeley) 06/23/92 8 */ 9 10 #include "param.h" 11 #include "systm.h" 12 #include "map.h" 13 #include "ioctl.h" 14 #include "proc.h" 15 #include "tty.h" 16 #include "time.h" 17 #include "resource.h" 18 #include "kernel.h" 19 #include "buf.h" 20 #include "wait.h" 21 #include "file.h" 22 #include "vnode.h" 23 #include "syslog.h" 24 #include "malloc.h" 25 #include "resourcevar.h" 26 #include "ptrace.h" 27 28 #include "machine/cpu.h" 29 #ifdef COMPAT_43 30 #include "machine/reg.h" 31 #include "machine/psl.h" 32 #endif 33 34 #include "vm/vm.h" 35 #include "vm/vm_kern.h" 36 37 /* 38 * Exit system call: pass back caller's arg 39 */ 40 /* ARGSUSED */ 41 rexit(p, uap, retval) 42 struct proc *p; 43 struct args { 44 int rval; 45 } *uap; 46 int *retval; 47 { 48 49 exit(p, W_EXITCODE(uap->rval, 0)); 50 /* NOTREACHED */ 51 } 52 53 /* 54 * Exit: deallocate address space and other resources, 55 * change proc state to zombie, and unlink proc from allproc 56 * and parent's lists. Save exit status and rusage for wait(). 57 * Check for child processes and orphan them. 58 */ 59 exit(p, rv) 60 register struct proc *p; 61 int rv; 62 { 63 register struct proc *q, *nq; 64 register struct proc **pp; 65 register struct vmspace *vm; 66 int s; 67 68 if (p->p_pid == 1) 69 panic("init died (signal %d, exit %d)", 70 WTERMSIG(rv), WEXITSTATUS(rv)); 71 #ifdef PGINPROF 72 vmsizmon(); 73 #endif 74 if (p->p_flag & SPROFIL) 75 stopprofclock(p); 76 MALLOC(p->p_ru, struct rusage *, sizeof(struct rusage), 77 M_ZOMBIE, M_WAITOK); 78 /* 79 * If parent is waiting for us to exit or exec, 80 * SPPWAIT is set; we will wakeup the parent below. 81 */ 82 p->p_flag &= ~(STRC|SPPWAIT); 83 p->p_flag |= SWEXIT; 84 p->p_sigignore = ~0; 85 p->p_sig = 0; 86 untimeout(realitexpire, (caddr_t)p); 87 88 /* 89 * Close open files and release open-file table. 90 * This may block! 91 */ 92 fdfree(p); 93 94 /* The next two chunks should probably be moved to vmspace_exit. */ 95 vm = p->p_vmspace; 96 #ifdef SYSVSHM 97 if (vm->vm_shm) 98 shmexit(p); 99 #endif 100 /* 101 * Release user portion of address space. 102 * This releases references to vnodes, 103 * which could cause I/O if the file has been unlinked. 104 * Need to do this early enough that we can still sleep. 105 * Can't free the entire vmspace as the kernel stack 106 * may be mapped within that space also. 107 */ 108 if (vm->vm_refcnt == 1) 109 (void) vm_map_remove(&vm->vm_map, VM_MIN_ADDRESS, 110 VM_MAXUSER_ADDRESS); 111 112 if (SESS_LEADER(p)) { 113 register struct session *sp = p->p_session; 114 115 if (sp->s_ttyvp) { 116 /* 117 * Controlling process. 118 * Signal foreground pgrp, 119 * drain controlling terminal 120 * and revoke access to controlling terminal. 121 */ 122 if (sp->s_ttyp->t_session == sp) { 123 if (sp->s_ttyp->t_pgrp) 124 pgsignal(sp->s_ttyp->t_pgrp, SIGHUP, 1); 125 (void) ttywait(sp->s_ttyp); 126 vgoneall(sp->s_ttyvp); 127 } 128 vrele(sp->s_ttyvp); 129 sp->s_ttyvp = NULL; 130 /* 131 * s_ttyp is not zero'd; we use this to indicate 132 * that the session once had a controlling terminal. 133 * (for logging and informational purposes) 134 */ 135 } 136 sp->s_leader = NULL; 137 } 138 fixjobc(p, p->p_pgrp, 0); 139 p->p_rlimit[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; 140 (void) acct(p); 141 #ifdef KTRACE 142 /* 143 * release trace file 144 */ 145 p->p_traceflag = 0; /* don't trace the vrele() */ 146 if (p->p_tracep) 147 vrele(p->p_tracep); 148 #endif 149 /* 150 * Remove proc from allproc queue and pidhash chain. 151 * Place onto zombproc. Unlink from parent's child list. 152 */ 153 if (*p->p_prev = p->p_nxt) 154 p->p_nxt->p_prev = p->p_prev; 155 if (p->p_nxt = zombproc) 156 p->p_nxt->p_prev = &p->p_nxt; 157 p->p_prev = &zombproc; 158 zombproc = p; 159 p->p_stat = SZOMB; 160 161 for (pp = &pidhash[PIDHASH(p->p_pid)]; *pp; pp = &(*pp)->p_hash) 162 if (*pp == p) { 163 *pp = p->p_hash; 164 goto done; 165 } 166 panic("exit"); 167 done: 168 169 if (p->p_cptr) /* only need this if any child is S_ZOMB */ 170 wakeup((caddr_t) initproc); 171 for (q = p->p_cptr; q != NULL; q = nq) { 172 nq = q->p_osptr; 173 if (nq != NULL) 174 nq->p_ysptr = NULL; 175 if (initproc->p_cptr) 176 initproc->p_cptr->p_ysptr = q; 177 q->p_osptr = initproc->p_cptr; 178 q->p_ysptr = NULL; 179 initproc->p_cptr = q; 180 181 q->p_pptr = initproc; 182 /* 183 * Traced processes are killed 184 * since their existence means someone is screwing up. 185 */ 186 if (q->p_flag&STRC) { 187 q->p_flag &= ~STRC; 188 psignal(q, SIGKILL); 189 } 190 } 191 p->p_cptr = NULL; 192 193 /* 194 * Save exit status and final rusage info, 195 * adding in child rusage info and self times. 196 */ 197 p->p_xstat = rv; 198 *p->p_ru = p->p_stats->p_ru; 199 p->p_ru->ru_stime = p->p_stime; 200 p->p_ru->ru_utime = p->p_utime; 201 ruadd(p->p_ru, &p->p_stats->p_cru); 202 203 /* 204 * Notify parent that we're gone. 205 */ 206 psignal(p->p_pptr, SIGCHLD); 207 wakeup((caddr_t)p->p_pptr); 208 #if defined(tahoe) 209 /* move this to cpu_exit */ 210 p->p_addr->u_pcb.pcb_savacc.faddr = (float *)NULL; 211 #endif 212 /* 213 * Clear curproc after we've done all operations 214 * that could block, and before tearing down the rest 215 * of the process state that might be used from clock, etc. 216 * Also, can't clear curproc while we're still runnable, 217 * as we're not on a run queue (we are current, just not 218 * a proper proc any longer!). 219 * 220 * Other substructures are freed from wait(). 221 */ 222 curproc = NULL; 223 if (--p->p_limit->p_refcnt == 0) 224 FREE(p->p_limit, M_SUBPROC); 225 226 /* 227 * Finally, call machine-dependent code to release the remaining 228 * resources including address space, the kernel stack and pcb. 229 * The address space is released by "vmspace_free(p->p_vmspace)"; 230 * This is machine-dependent, as we may have to change stacks 231 * or ensure that the current one isn't reallocated before we 232 * finish. cpu_exit will end with a call to swtch(), finishing 233 * our execution (pun intended). 234 */ 235 cpu_exit(p); 236 /* NOTREACHED */ 237 } 238 239 #ifdef COMPAT_43 240 owait(p, uap, retval) 241 struct proc *p; 242 register struct args { 243 int pid; 244 int *status; 245 int options; 246 struct rusage *rusage; 247 int compat; 248 } *uap; 249 int *retval; 250 { 251 252 #ifdef PSL_ALLCC 253 if ((p->p_md.md_regs[PS] & PSL_ALLCC) != PSL_ALLCC) { 254 uap->options = 0; 255 uap->rusage = 0; 256 } else { 257 uap->options = p->p_md.md_regs[R0]; 258 uap->rusage = (struct rusage *)p->p_md.md_regs[R1]; 259 } 260 #else 261 uap->options = 0; 262 uap->rusage = 0; 263 #endif 264 uap->pid = WAIT_ANY; 265 uap->status = 0; 266 uap->compat = 1; 267 return (wait1(p, uap, retval)); 268 } 269 270 wait4(p, uap, retval) 271 struct proc *p; 272 struct args { 273 int pid; 274 int *status; 275 int options; 276 struct rusage *rusage; 277 int compat; 278 } *uap; 279 int *retval; 280 { 281 282 uap->compat = 0; 283 return (wait1(p, uap, retval)); 284 } 285 #else 286 #define wait1 wait4 287 #endif 288 289 /* 290 * Wait: check child processes to see if any have exited, 291 * stopped under trace, or (optionally) stopped by a signal. 292 * Pass back status and deallocate exited child's proc structure. 293 */ 294 wait1(q, uap, retval) 295 register struct proc *q; 296 register struct args { 297 int pid; 298 int *status; 299 int options; 300 struct rusage *rusage; 301 #ifdef COMPAT_43 302 int compat; 303 #endif 304 } *uap; 305 int retval[]; 306 { 307 register int nfound; 308 register struct proc *p, *t; 309 int status, error; 310 311 if (uap->pid == 0) 312 uap->pid = -q->p_pgid; 313 #ifdef notyet 314 if (uap->options &~ (WUNTRACED|WNOHANG)) 315 return (EINVAL); 316 #endif 317 loop: 318 nfound = 0; 319 for (p = q->p_cptr; p; p = p->p_osptr) { 320 if (uap->pid != WAIT_ANY && 321 p->p_pid != uap->pid && p->p_pgid != -uap->pid) 322 continue; 323 nfound++; 324 if (p->p_stat == SZOMB) { 325 retval[0] = p->p_pid; 326 #ifdef COMPAT_43 327 if (uap->compat) 328 retval[1] = p->p_xstat; 329 else 330 #endif 331 if (uap->status) { 332 status = p->p_xstat; /* convert to int */ 333 if (error = copyout((caddr_t)&status, 334 (caddr_t)uap->status, sizeof(status))) 335 return (error); 336 } 337 if (uap->rusage && (error = copyout((caddr_t)p->p_ru, 338 (caddr_t)uap->rusage, sizeof (struct rusage)))) 339 return (error); 340 /* 341 * If we got the child via a ptrace 'attach', 342 * we need to give it back to the old parent. 343 */ 344 if (p->p_oppid && (t = pfind(p->p_oppid))) { 345 p->p_oppid = 0; 346 proc_reparent(p, t); 347 psignal(t, SIGCHLD); 348 wakeup((caddr_t)t); 349 return (0); 350 } 351 p->p_xstat = 0; 352 ruadd(&q->p_stats->p_cru, p->p_ru); 353 FREE(p->p_ru, M_ZOMBIE); 354 if (--p->p_cred->p_refcnt == 0) { 355 crfree(p->p_cred->pc_ucred); 356 FREE(p->p_cred, M_SUBPROC); 357 } 358 359 /* 360 * Finally finished with old proc entry. 361 * Unlink it from its process group and free it. 362 */ 363 leavepgrp(p); 364 if (*p->p_prev = p->p_nxt) /* off zombproc */ 365 p->p_nxt->p_prev = p->p_prev; 366 if (q = p->p_ysptr) 367 q->p_osptr = p->p_osptr; 368 if (q = p->p_osptr) 369 q->p_ysptr = p->p_ysptr; 370 if ((q = p->p_pptr)->p_cptr == p) 371 q->p_cptr = p->p_osptr; 372 373 /* 374 * Give machine-dependent layer a chance 375 * to free anything that cpu_exit couldn't 376 * release while still running in process context. 377 */ 378 cpu_wait(p); 379 FREE(p, M_PROC); 380 nprocs--; 381 return (0); 382 } 383 if (p->p_stat == SSTOP && (p->p_flag & SWTED) == 0 && 384 (p->p_flag & STRC || uap->options & WUNTRACED)) { 385 p->p_flag |= SWTED; 386 retval[0] = p->p_pid; 387 #ifdef COMPAT_43 388 if (uap->compat) { 389 retval[1] = W_STOPCODE(p->p_xstat); 390 error = 0; 391 } else 392 #endif 393 if (uap->status) { 394 status = W_STOPCODE(p->p_xstat); 395 error = copyout((caddr_t)&status, 396 (caddr_t)uap->status, sizeof(status)); 397 } else 398 error = 0; 399 return (error); 400 } 401 } 402 if (nfound == 0) 403 return (ECHILD); 404 if (uap->options & WNOHANG) { 405 retval[0] = 0; 406 return (0); 407 } 408 if (error = tsleep((caddr_t)q, PWAIT | PCATCH, "wait", 0)) 409 return (error); 410 goto loop; 411 } 412 413 /* 414 * make process 'parent' the new parent of process 'child'. 415 */ 416 void 417 proc_reparent(child, parent) 418 register struct proc *child; 419 register struct proc *parent; 420 { 421 register struct proc *o; 422 register struct proc *y; 423 424 if (child->p_pptr == parent) 425 return; 426 427 /* fix up the child linkage for the old parent */ 428 o = child->p_osptr; 429 y = child->p_ysptr; 430 if (y) 431 y->p_osptr = o; 432 if (o) 433 o->p_ysptr = y; 434 if (child->p_pptr->p_cptr == child) 435 child->p_pptr->p_cptr = o; 436 437 /* fix up child linkage for new parent */ 438 o = parent->p_cptr; 439 if (o) 440 o->p_ysptr = child; 441 child->p_osptr = o; 442 child->p_ysptr = NULL; 443 parent->p_cptr = child; 444 child->p_pptr = parent; 445 } 446